In perfect binding, single sheets and/or folded signatures previously assembled to form a loose book block are processed at the spine thereof by routing and glue is then applied thereto. A cover is then pressed against the spine of the book block and thereby rigidly glued thereto. A distinction is made between the production of printed products having a flexible cover and those having a rigid cover (hard cover), that is to say between what are known as soft-cover and hard-cover products.
When binding a soft-cover book, the spine of the loose book block is firstly routed and glue is then applied to the spine before the cover is applied. The book bound in this manner can then be cut to the desired size in a three-knife trimmer.
In hard-cover production, the loose book block is generally provided, after routing, with what are known as endsheets, which are glued to the two sides of the book block by a thin glue line. In the finished book, these endsheets serve as a hinge to the cover. A lining strip which consists of a woven material and overlaps the spine of the book block is then applied, that is to say, glued to the spine of the book block using a hotmelt glue or PUR, for example. The lining strip serves to reinforce the book block and holds it together. After the endsheet and the lining strip have been pressed on, the book block is provided with a rigid cover.
Alternatively, a sewn book block can also be glued to a rigid or a flexible cover.
Regardless of whether a soft-cover product or a hard-cover product is to be produced from a sewn or from a perfect-bound book, in conventional devices two steps must be carried out in order to apply the cover or the lining strip. The lining strip or the cover is firstly glued to the spine of the book block in a first station and then pressed against the book block in a second station.
European patent application EP1344655 A2 discloses a device for producing bound book blocks, in particular for short runs. The device comprises an endsheet feeding means and a feeding device for lining strips which cooperates with a cutting means. The lining strip is cut to size and then glued to the spine, to which glue has previously been applied, of the book block. The book block is then transported into a further processing station, whereupon side glue application takes place. As an alternative to feeding endsheets and lining strips for producing a hard-cover book, this device can also be used to feed a flexible cover for the purpose of producing a soft-cover book. In the further processing station, the lining strip, which has been glued to the spine of the book block, or the flexible cover is pressed against the book block in the spine region and in the side region. The pressing operation requires correspondingly formed additional devices, for example a pressing station.
DE10005493 A1 discloses a method and a device for feeding covers and/or lining strips to a perfect binder. In this solution, which has a low binding capacity and is also suitable only for short runs, the covers and/or lining strips, which are fed separately from one another, are taken up by means of a gripper drum and conveyed for rolling onto a book block moved by a transport means. In a solution of this type, transporting the covers on the surface of the gripper drum becomes increasingly difficult as the rigidity of the covers increases. In addition, the quality of the bound book block can be influenced negatively by relatively rigid covers being deformed on the surface of the gripper drum.
The devices for applying endsheets and lining strips used in the production of hard-cover products often require prolonged changeover times because these devices are located in the region of a book conduit which is used to transport the book block and can only be set to one product thickness in each case. In this context it must be ensured that the glue does not dry while the book block is being transported to the pressing station; for this reason the transport speed must be adapted to the glue used, for example dispersion glue, hotmelt glue or PUR. A device of this type also has relatively large space requirements. These aspects contribute to the fact that the perfect binder is firstly of an overall size which is problematic for the user and secondly relatively expensive.